Purpose of the Scale

The main objective of the Fatigue Assessment Scale [FAS-10] is to evaluate the negative effects caused by chronic exhaustion and fatigue, without distinguishing between the different contributing factors during the assessment process. Instead, it encompasses all the defining characteristics of fatigue, both on a physical and psychological level.

Scale Analysis

The Fatigue Assessment Scale [FAS-10] was developed in 2003 by Michielsen et al. (2003).
It consists of ten items, five of which are related to physical exhaustion and the other five to the psychological fatigue experienced by individuals.

Scale Scoring

For the scoring of the Fatigue Assessment Scale [FAS-10], a five-point Likert scale is used, where the value 1 corresponds to “never” and the value 5 to “always.”
Specifically, items 4 and 10 are reverse-scored.
Lower levels of exhaustion are indicated by scores close to 10, while higher levels of fatigue are reflected by scores reaching up to 50.

Statistical Analysis of the Scale

The total score of the Fatigue Assessment Scale [FAS-10] is calculated after accounting for the reverse scoring of items 4 and 10.
Patients are categorized as “not fatigued” if their total score is below 22, and as “fatigued” if their score is equal to 22.
Additionally, individuals are considered “severely fatigued” when their score is greater than or equal to 35.

Validity and Reliability of the Scale

The psychometric Fatigue Assessment Scale [FAS-10] demonstrates internal consistency.
Specifically, the internal reliability of the scale was examined among Greek patients with chronic diseases by Alikari et al. (2016), and was found to be 0.761.

References

Greek Bibliography
Alikari, V., Fradelos, E., Sachlas, A., Panoutsopoulos, G., Giatrakou, S., Stathoulis, I., … & Mpampatsikou, F. (2016).
Reliability and validity of the Greek version of the “Fatigue Assessment Scale.” Archives of Hellenic Medicine, 33(2).
International Bibliography
De Vries, J., Michielsen, H., Van Heck, G. L., & Drent, M. (2004).
Measuring fatigue in sarcoidosis: The Fatigue Assessment Scale (FAS). British Journal of Health Psychology, 9(3), 279–291.
Michielsen, H. J., De Vries, J., & Van Heck, G. L. (2003).
Psychometric qualities of a brief self-rated fatigue measure: The Fatigue Assessment Scale. Journal of Psychosomatic Research, 54(4), 345–352.